It may just be coincidental that Animal Collective released both Animal Crack Box and Merriweather Post Pavilion in the final year of the 00s. But the two releases-- one a long-awaited mix of early experimental work, the other a massive crossover success-- frame the band's progress pretty neatly. Over the course of the decade, a group that started off noisy and challenging grew into one of indie rock's most well-known and key acts, opening their sound to audiences who became increasingly more receptive to "difficult" music.

Animal Collective weren't the only noisy act to take that path this decade. The road from ACB to MPP is also emblematic of how noise music-- underground sounds that value volume and dissonance over structure or melody-- evolved in the 00s. It grew from disconnected, homegrown scenes to something more recognized and more diverse, more sophisticated and more direct, more ambitious and more reverent, and more open to new sounds, new approaches, and new venues. Thanks to forward-thinking labels and festivals, the umbrella of what could be called "noise" widened considerably. Many followers now think of it as not just harsh sonic assaults, but also abstract improvisation, ecstatic free jazz, lo-fi pop, outsider avant-rock, minimalist drone, power electronics, and more.

You can posit many reasons for this growth-- the increase in local scenes working cheaply and communally; the Internet helping them grow and connect quickly; indie rock's mainstream drift driving more adventurous fans to edgier music; noise-leaning bands of the 90s-- from the Flaming Lips to Sonic Youth-- encouraging people to seek new sounds. But whatever made it happen, few would deny that noise has come a long way since the turn of the century.

In fact, as the 2000s began, noise and the rest of the experimental underground were floundering a bit. Many interesting acts of the 90s-- Whitehouse, the Dead C, Sun City Girls, the Japanese throng headed by Merzbow, Boredoms, and Keiji Haino-- were still at it, but their activity became sparser and less widespread. And the possibility of overground exposure hinted at previously-- such as Siltbreeze's distribution deal with Matador, or Boredoms signing to Warner Brothers-- was waning.

In addition, computers became an obstacle. There was much talk in the 90s about how computer-based music was the future, and many noise artists took advantage of the possibilities. But noise gets most of its vitality from performance-- take the Sun City Girls' costumed carnivals, Harry Pussy's screaming freakouts, or the art-prank spectacle of the Boredoms' Eye Yamatsuka driving a bulldozer into a club as the audience ran for cover. Computers threatened to sap that energy, as sitting on stage and staring at a laptop became commonplace. At the 2000 Transmissions Festival, a burgeoning showcase for experimental music, I sat through six artists in a row who barely moved behind their glowing screens. The practice got rote so quickly that complaints were rampant. Even folk legend John Fahey spent part of his Transmissions set making fun of laptop jockeys, mock-marveling at how his loop pedals could make music without any visible effort.

Perhaps as a reaction to those staid presentations, new noise scenes emerged that revitalized the spectacle of performance. The most important came from two surprising locales, Rhode Island and Michigan. In both places, bands collaborated, shared bills, ran labels, and generally avoided self-destructive infighting. They were filled with life-long music freaks for whom the Internet offered new potential for creative discourse and the kind of simple networking that gets bands playing in each other's basements and talking up each other's music. And both scenes had been bubbling since the mid-90s. So when a void needed to be filled in the 00s, they were up to the task.

In Providence, R.I., an arty community grew up around the Rhode Island School of Design and the performance space Fort Thunder. It produced one of the most important noise labels of the decade, Load Records, and two of the most significant bands, Black Dice and Lightning Bolt. All three trafficked in a kind of art school version of 90's scum rock, mixing in overloaded effects, damaged electronics, and gimmicks like masks and in-mouth mics. (Load also highlighted the darker side to Providence noise, embodied in bands such as Kites, White Mice, and Landed.)

Ultimately, it was Lightning Bolt's amazing live shows that took the Providence scene farthest. Setting up on club floors rather than stages, and starting mere seconds after the previous band, the duo of Brian Gibson and Brian Chippendale flailed away while engulfed by thrashing crowds. Albums such as 2003's Wonderful Rainbow were mini-masterpieces of churning energy, but it was their tour-doc DVD ThePower of Salad that best displayed their remarkable effect on crowds. These were audiences who presumably had never bounced around to noise, which even at its most sensational had attracted mostly chin-scratchers. It all prompted declarations that Lightning Bolt had revitalized DIY punk of the 80s-- that "hardcore was back." But perhaps more accurately, Lighting Bolt made noise punk again.

The same could be said of the Michigan scene centered on homegrown labels American Tapes and Hanson Records. In 2001, the two jointly released Dread, the first record by Ann Arbor's Wolf Eyes. That debut was somewhat sparse, but soon the trio of Nate Young, John Olson, and Aaron Dilloway would have as many fists pumping and heads pounding as Lighting Bolt did. "When we started playing we wanted to make music that people would have fun to," Dilloway told The Wire. Olson agreed: "We're trying to bring the good times to the noise, totally. There's a really good vibe going on right now, where it's a bunch of kids who want to have fun but want to listen to interesting music."

Yet Wolf Eyes never sounded pleasant. Even as the band signed to Sub Pop, opened for Sonic Youth, and nabbed a spot on an ill-fated Lollapalooza tour-- taking them closer to the mainstream than even the more accessible Lightning Bolt-- their music remained bracing and pure. In fact, their two Sub Pop albums-- 2004's Burned Mind and 2006's Human Animal-- are among their most difficult. Stirring a stew of influences-- the dirge of Swans, the clang of Einstürzende Neubauten, even the dark hardcore of the Misfits-- the band lurched from blasted beat to dense feedback.

But it was Wolf Eyes' cage-match live act that got their crowds so pumped. They threw themselves into the kind of noise that their predecessors stood glumly behind, as they banged on homemade instruments, huge gongs, and even weaponry. (Olson did the Boredoms' Eye one better by swinging a mace, which at one show accidentally gouged him and produced a cascade of blood.) It got to the point where Wolf Eyes shows were likened to underground frat parties, and certainly the audience enthusiasm could spill over into lunkhead land. But the fact that people became so viscerally involved was testament to how Wolf Eyes had made noise so engaging.

The Midwest scene that spawned Wolf Eyes multiplied quickly. There was Hair Police, a trio who looked like a rock band but sounded like a broken radio in a blender (and whose Mike Connelly would eventually replace Dilloway in Wolf Eyes); Burning Star Core, featuring the drones of violinist and vocalist C. Spencer Yeh; Sick Llama, equally capable of minimalist ambience and exploding blasts; 16 Bitch Pile-Up, a darkly raucous female collective who eventually landed in the Bay Area; Hive Mind, whose Greh Holger churned out dense electric fields and ran the vital Chondritic Sound label; and most recently Emeralds, blasting out kraut-style clouds in Cleveland.

Those acts' camaraderie is evident in their sonic similarities and frequent collaborations, but neither the Michigan nor Providence scenes were insular. All these groups got out of town and played shows, rather than just spewing out CD-Rs from their basements and bedrooms. This led to a new global scene built partially via the Internet, but mostly by good old-fashioned touring.

As early as 2003, Olson invited Black Dice to trek to Ann Arbor. Within hours of their arrival, the groups decided to collaborate on one of the best noise records of the decade, Wolf Eyes and Black Dice. Similar intersections would proliferate throughout the 00s, connecting groups like the Skaters, Yellow Swans, and Axolotl in San Francisco, to John Wiese, Robedoor, and the Cherry Point in L.A., to Nautical Almanac and WZT Hearts in Baltimore, to Magik Markers, Bill Nace, and Chris Corsano in Western Massachusetts. Such cross-pollinations made for a convivial scene, especially remarkable given the music's reputation for aggression and confrontation. Global noise became a local phenomenon, a web of scenes equally devoted to each other and the world around them.